Method for processing knit goods and the like

ABSTRACT

A running web of knit material or the like is processed on a continuous basis and in a tensionless open width condition by means of a moving belt, co-extensive with the web, which carries the web first through a wet-out stage where it is scoured in a solution or otherwise treated and then to a drying stage. The fabric is carried in tight contact against a plurality of heated rotary drums which cause the entrained liquid to evaporate from the fabric. A condensate system is provided for condensing and recovering the solution.

United States Patent 11 1 Stevens, Jr.

1451 Apr. 9, 1974 METHOD FOR PROCESSING KNIT GOODS AND THE LIKE [75] Inventor: Brooks Stevens, Jr., Concord, Mass.

[73] Assignee: Riggs & Lombard, Inc., Lowell,

Mass.

22 Filed: Dec. 13, 1971 21 Appl. No.: 207,401

Related US. Application Data [62] Division of Ser. No. 881,50l, Dec. 2, 1969, Pat. No.

52 us. (:1. .Q 8/151 [5 l] Int. Cl B050 3/132, D06f 43/06 [58] Field of Search 68/19.l; 8/l5l [56] References Cited FOREIGN PATENTS OR APPLICATIONS Belgium ...,....,68/l9.l

Primary E.\'aminerWilliam I. Price Attorney. 48.6" W E KmfMQEQQLAIFEIFJHL 9919 .1 Bello 5 7 ABSTRACT A running web of knit material or the like is processed on a continuous basis and in a tensionless open width condition by means of a moving belt, co-extensive with the web, which carries the web first through a wet-out stage where it is scoured in a solution or 0therwise treated and then to a drying stage. The fabric is carried in tight contact against a plurality of heated rotary drums which cause the entrained liquid to evaporate from the fabric. A condensate system is provided for condensing and recovering the solution.

1 Claim, 2 Drawing Figures METHOD FOR PROCESSING KNIT GOODS AND THE LIKE This is a division of application Ser. No. 881,501 filed Dec. 2, 1969, now U.S. Pat. No. 3,643,475.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to the production of textile material and more particularly is directed towards a new method and associated apparatus for continuously processing a running fabric web in a tensionless open width or flat tubular condition through a scouring stage or the like and then through a drying stage.

2. History of the Prior Art In the production of many types of fabrics, impurities such as nitrogenous matter, mineral matter, pectic material, waxes and miscellaneous pigments, oil, greases and resins are removed by various soil and foreign matter cleaning processes. One such process is known as scouring in which the fabric is subjected to a scouring solution for a suitable time and typically in a heated condition. The process can be carried out on a batch or a continuous basis with certain types of materials. Tightly woven cotton, for example, is sufficiently strong that it may be passed in open width condition back and forth over rollers into and out of solution and through the drying stages without distorting the fabric. However, loosely woven knit goods or other materials having high stretch strain ratios heretofore could not be handled in this fashion since any longitudinal or lateral tension on the material would produce considerable distortion and, in practice, materials of this nature generally are processed on a batch basis. Accordingly, it is an object of the present invention to provide a new and improved method and associated apparatus for processing fragile materials such as knit goods on a fast, efficient, continuous basis without introducing any appreciable lateral or longitudinal tension in the material. Another object of this invention is to provide improvements in the art of bleaching and scouring fragile fabric webs.

SUMMARY OF THE INVENTION This invention features a novel method and associated apparatus for processing fragile goods such as knit materials and the like wherein the web of material is guided into face-to-face superimposed position over a belt that is co-extensive with the web at least during the processing thereof and which transports the fabric in open width or flat tubular condition about rollers in a scouring state or the like and thence into adrying stage where the material is heated to evaporate liquid carried from the scouring stage. Upon the completion of the drying operation, the belt and material are separated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view in side elevation of an apparatus made according to the invention, and,

FIG. 2 is a view similar to FIG. 1 but showing a modification thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and to FIG. 1 in particular there is illustrated an apparatus for processing on a continuous basis running fabric web 10, through solvent scouring operations and the like. As employed herein the term web shall include woven and nonwoven materials, knit goods and the like and which may be in a flat tubular or openwidth condition. The apparatus is particularly useful in the continuous dry cleaning of knit goods, for example, which are subject to lateral and longitudinal distortion when tensioned.

The apparatus is generally organized about a tank 12 the walls of which are closed except for entrance and exit slots 14 and 16 which may be provided with suitable seals. The tank 12 is divided generally into a wetout section 18 on the left-hand side thereof as viewed in FIG. 1 and a drying section at the right-hand end. The web 10 may be guided from a supply roll 22 or directly from a prior process into face-to-face open width superimposed engagement with a continuous belt or apron 24 at least as wide as the web 10. The apron 24 runs continuously in a closed loop from one end of the tank to the other and carries the web 10 substantially fully supported, without appreciable tension, through the apparatus.

In order to keep any running fabric, especially in open-width form, tracking properly a certain minimum tension is required. If the web is of a type such as knit material which is subject to lengthwise and widthwise distortion during processing, or if the material has a high stretch-strain ratio, such tension is to be avoided. According to the present invention, any such tension in the web is substantially eliminated by the use of the apron 24. In the preferred form of the invention, the apron is ofa tough flexible material, such as fibre-glass, wire, nylon or the like, which is inert to the liquid employed and fabricated so as not to stretch to any appreciable extent when longitudinally tensioned. The belt may be porous or imperforate although a porous, o'penwork belt is preferred to allow better circulation of the solution through the web as well as to enhance heat transfer to the web. In addition to the apron 24 a second apron 26, shown in dotted line in FIG. 1, may be employed to sandwich the web 10 as it is carried through the apparatus. The sandwiching arrangement is particularly useful where processing discontinuous webs.

In any event, the web 10 together with the apron 24 pass over guide rolls 28, 30 and 32 and are guided down through the slot opening 14 into the tank 12. The superimposed web and apron then pass into a sump containing a quantity of liquid cleaning solvent, for example. The bath of solvent is contained in the lower left-hand corner of the tank 12 in the sump defined by walls 34 and 36 as well as by the side walls of the tank. The web and apron pass in and out of the bath by means of a series of rolls 38 and 40, etc., the lower rolls being submerged and the upper rolls preferably disposed above the surface of the liquid. During their passage through the solvent the surface tension of the liquid aids in maintaining the web and apron in close contact. The rolls 38 and 40 in the preferred embodiment of this invention are made in accordance with U.S. Pat. No. 3,401,541 wherein each submerged roll is arranged to substantially float in the liquid to reduce frictional bearing drag.- Further, each roll is mounted in double bearings with one bearing of each double bearing being driven by means of a variable speed control mechanism so that the bearing drag is reduced substantially to zero. A slight and positive forward urge is given to each roll while a slight upward and downward tension is given to the web by the zero weight submerged rolls. The rolls 38 and 40 substantially eliminate hearing drag and at the same time produce no appreciable tension on the web or apron travelling over these rolls.

In the preferred form of this invention rotary impellers 44 are mounted in the tank below the liquid surface and between each course of travel of the web and apron as they pass in and out of the bath. The impellers are employed to flush the solvent through the web to insure optimum interaction between the solvent and the'web and are made in accordance with US. application Ser. No. 815,329 filed Apr. 1 l, 1969 by Harold R. Wilcox and entitled Continuous Open Width Washer now US. Pat. No. 3,640,101.

Briefly, the impellers 44 are comprised of central rolls or cores 46 driven by a simple drive system and each provided on its outer surface with spaced longitudinal abutments 48 such as rods or the like whereby the liquid will be pulsed against the open face of the fabric carried by the apron to enhance the liquid to fabric contact. The impellers 46 are each of a length corresponding at least to the width of the web and arranged in groups on opposite sides of the web so that each section of the web will be subjected to the action of pairs I of impellers. Preferably the abutments 48 are cylindrical in cross-section or at least rounded on their outer portions to eliminate any chance of scoring or otherwise damaging the fabric should it come in contact with the impellers.

After the web and apron have made a number of passes in and out of the solvent, they travel upwardly against an idler roller 50 and are subjected to a spray of solvent from a transverse nozzle 52 shielded by a baffle 54. Clean solvent is delivered through the spray nozzle by means of a pump (not shown) from a solvent storage tank, typically located at the side of the main housing. In practice, the solvent in the storage tank is recovered by condensation, filtered or otherwise cleaned before re-use.

Once past the spray nozzle 52, the web and apron travel over an idler roll 56 along a more or less horizontal path into the bite of a pair of nip rolls S8 and 60 which squeeze excess solvent from the web. Between the roll 56 and the nip rolls additional clean solvent is washed over the width of the web from an inclined pudding board 62 which receives clean condensate from a condenser 64 and directs the flow onto the horizontal reach of the web to wash out any residual particles in the web. From the nip rolls the web and apron travel about a tensioning roller 66 which maintains sufficient longitudinal tension on the apron to insure proper driving contact between the apron and the various rolls at least one of which is driven.

A baffle 68 is disposed below the nip rolls to direct the liquid squeezed from the web back down into the sump tank for re-use. Mounted under the baffle 68 is a condenser 70 which drains onto an inclined channel 72 extending through the drying section of the tank and back into the sump.

in the preferred embodiment, the drying section of the tank includes a plurality of rotary heated cylinders or cans 74, all relatively large in diametcrand typically heated by steam under a pressure on the order of 100 psi. The cylinders 74 serve to heat the web sufficiently to cause any solvent entrained in the web to vaporize into the tank atmosphere. By using the apron to support it, the web can be held in close contact with the outer surfaces of the cylinders foroptimum heat transfer and thereby make the most efficient use of the drying stage. By the time the web and apron have traveled through the drying stage, substantially all of the solvent will have been vaporized from the web and apron which then are moved over an idler roll 76 out through the exit slot 16 and over rolls 78 and 80. The web 10 is then separated from the apron and rolled up or passed onto further processing. The apron 24 then passes through a pair of expander rolls 82 and 84 which serve to maintain the apron in a smooth, fully open width condition prior to returning to the starting point to pick up a fresh section of web. Where a double apron is employed, it also is returned to the starting point and, again, expander rolls or their equivalent may be utilized.

Below the group of drying cans is a funnelled bottom wall 86 for collecting condensed solventvaporized by the drying cans. In the FIG. 1 embodiment a relatively large condenser (not shown) is mounted along side the main tank and the vaporized solvent from the drying stage is directed by duct work to the main condenser. The resulting condensate is passed through a separator or other purifying means prior to re-use. A small condenser 88 is provided at the right-hand end of the tank and also discharges onto the inclined channel 72 for return to the sump within the main unit.

I It will be appreciated that the apron or aprons permit any fragile web material to be held tightly in direct contact against the surface of the heated cylinders without stretching the fabric. Double aprons will pro vide tight contact against all cylinders while a single apron will offer best contact as the web is carried down under the lower surfaces of the cylinders. Thus the material may be washed and dried quickly and easily without being subjected to distortion, stretching or the like.

The entire process may be carried out without wetting the material with water and this has an advantage over steam drying techniques. If steam is sprayed directly against the fabric to cause the solvent to vaporize, the steam will condense and wet the material. In addition, the water and solvent will then have to be separated before the solvent can be re-used. The present invention eliminates the problem of wetting the material with water and delivers the material in a relaxed, undistorted condition on a continuous basis.

Referring now to FIG. 2 of the drawings there is illustrated a modification of the invention and in this embodiment all of the recovery stills are located within the main tank housing. As shown in H6. 2 the wet-out and the drying sections are arranged in a manner similar to FIG. 1, however, in this embodiment condensate from the drying stage as well as overflow from the solvent sump tank are collected in a condensate well 100 at the base of a main tank housing 12'. Disposed in the well are cooling coils and suitable conduits and pumps (not shown) are provided for delivering the condensed solvent into the sump tank, as required. The washing tank is provided with a washing apparatus of the sort disclosed in commonly assigned co-pending application Ser. No. 670,837 filed Sept. 27, 1967 by Harold R. Wilcox and entitled Textile Washing Apparatus; new

Mounted in generally tangential relation to the drum 102 are relatively small planetary reels 104, each provided with an array of evenly spaced smaller nip rolls 106 adapted to mesh with the corrugations of the larger drum 102. The web and belt are fed into the liquid around the drum and out. As the corrugated drum rotates along with the planetary reels, the nip rolls force the web and belt into the corrugations, squeezing the liquid through the fabric and enhancing the contact between the web and the liquid.

In order to improve the support of the web during its passage through the liquid, a continuous belt or apron 108 is illustrated in the FIG. 2 embodiment and may also be included in the FIG. 1 embodiment if the second belt 26 is not employed. The belt 108 travels about rolls 110 and 112 which guide the belt 108 into and out of superimposed contact with the web and belt 24'.

While the invention has been described with particular reference to the illustrated embodiments, it will be understood that numerous modifications thereto will appear to those skilled in the art. For example, in place of a continuous closed loop belt a belt coextensive with the web in length as well as width may be employed to support the web in its travel through the apparatus. Also other means may be employed to vaporize solvent from the web.

Having thus described the invention, what I claim and desire to obtain by Letters Patent of the United States is:

l. The method of processing a running web of knit material or the like comprising the steps of,

a. conveying said web continuously and substantially fully supported over at least one face thereof in a flat relaxed condition first through a bath of liquid along reversing parallel vertical paths about submerged floatation idler rolls and exposed tensionless driven rolls,

b. flushing said liquid through said web while in said bath,

c. physically removing a portion of said liquid from said web, and,

d. conveying and fully supporting said web in a flat relaxed condition about a plurality of heated rotary drums for directly heating said supported web sufficiently to vaporize the remaining portion of said liquid. 

